E432: Resection of Abdominal Wall Desmoid Tumours: A Single-Center Case Series

Abdominal wall desmoids (desmoid type fibromatosis) are locally aggressive tumors. Despite consensus-based guidelines which cite surgery or systemic treatment to be considered for symptomatic tumors, surgery is rarely offered as a first line treatment in North America. Poor cosmesis/functional outcomes and recurrence rates as high as 77% are reported. The relationship between local recurrence and surgical margin is unclear, with case series reporting recurrence independent of margin status. This study reports outcomes following wide local resection of desmoid tumors followed by abdominal wall reconstruction by a single surgical oncologist.

Methods:

Surgery was offered to all patients referred with symptomatic abdominal wall desmoid tumors. Patients who opted for surgical resection with wide margins followed by abdominal wall reconstruction from 2005 to 2021 were included for retrospective analysis. Records were reviewed for clinical presentation, operative technique, postoperative morbidity, recurrence, and patient satisfaction.

Results:

Sixteen patients were included. All were female, 75% (n=12) had a history of pregnancy, and one had a diagnosis of familial polyposis syndrome. No tumors were associated with a previous surgical incision. Two patients presented upon failing systemic therapy. All underwent preoperative core biopsy and were discussed at multidisciplinary sarcoma tumour boards. All specimens were reviewed by a sarcoma pathologist. The mean tumor diameter was 8.3 +/- 4.1cm, with a mean clinical deficit of 14.4 +/- 3.5cm. The peritoneum was mobilized in all and closed primarily in 75% (n=12). All patients underwent abdominal wall reconstruction. Fascial/muscle deficit was closed with double layer prolene mesh reconstruction (n=11, 68.8%), composite polypropylene mesh (n=3, 18.8%), or primary closure with polypropylene onlay mesh (n=2, 12.5%). All skin deficits were closed with local advancement flaps. One patient received adjuvant radiation. No grade 2-5 complications were observed. Three grade 1 complications were reported: keloid scar treated with intralesional hydrocortisone, groin pain (tumor abutted the pubic bone, treated with periosteal cauterization and radiation), and one patient was dissatisfied with abdominal contour at 2 years (following weight gain). There were no recurrences at a mean follow up of 123.6 +/-68 months. All reported satisfaction with cosmesis and treatment at one year post operatively.

Conclusions:

Given the absence of recurrence and limited observed morbidity, this study supports wide local excision of symptomatic abdominal wall desmoids.